Undisplaced intracapsular hip fractures: results of internal fixation in 375 patients.

Three hundred seventy-five patients with an undisplaced intracapsular proximal femoral fracture were treated with internal fixation. Nonunion occurred in 24 patients (6.4%) and avascular necrosis occurred in 15 patients (4.0%). Reoperation with an arthroplasty was required in 29 patients (7.7%). The age, walking ability of the patient, and degree of impaction seen on the anteroposterior radiograph or angulation seen on the lateral radiographs were of statistical significance in predicting fracture healing complications. The results for this series of patients were compared with the results in published reports identified by a comprehensive literature search. Summation of the results indicated that the overall risk of redisplacement or nonunion of the fracture was 4.3% (95% confidence interval, 3.4%-5.3%) with internal fixation of an undisplaced intracapsular fracture. For conservative treatment, the failure rate was 19.6% (95% confidence interval, 17.2%-22.1%). The incidence of avascular necrosis with internal fixation at 1 year was 2.2% (95% confidence interval, 1.6%-2.9%) compared with 2.8% (95% confidence interval, 1.9%-4.0%) with nonoperative treatment. Internal fixation is recommended for the treatment of undisplaced intracapsular hip fractures.